Recipe adapted from the Produce for Better Health Foundation.
Heat oven to 450°F.
Coat a 9 x 13-inch baking dish with cooking spray. Then add the carrots, onion, and oil.
Toss vegetables to coat with oil, then spread to make a single layer.
Roast, stirring occasionally, until the carrots are lightly browned and just tender (20 to 25 minutes). Add parsley, salt, and pepper, and toss to coat.